using System;
using System.Collections.Generic;
using System.Text;
using Fuzzware.Common;
using Fuzzware.Common.Encoding;
using Fuzzware.Common.DataSchema;

namespace Fuzzware.ConvertFromXML.Processors
{
    public class CRC32Fn
    {
        //private static uint CRC32Value;
        private static uint[] CRC32Table = {
0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F, 0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988, 0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 
0x1DB71064, 0x6AB020F2, 0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7, 0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9, 0xFA0F3D63, 0x8D080DF5, 
0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172, 0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C, 0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59, 
0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423, 0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924, 0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 
0x76DC4190, 0x01DB7106, 0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433, 0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D, 0x91646C97, 0xE6635C01, 
0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E, 0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950, 0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65, 
0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7, 0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0, 0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 
0x5005713C, 0x270241AA, 0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F, 0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81, 0xB7BD5C3B, 0xC0BA6CAD, 
0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A, 0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84, 0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1, 
0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB, 0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC, 0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 
0xD6D6A3E8, 0xA1D1937E, 0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B, 0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55, 0x316E8EEF, 0x4669BE79, 
0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236, 0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28, 0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D, 
0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F, 0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38, 0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 
0x86D3D2D4, 0xF1D4E242, 0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777, 0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69, 0x616BFFD3, 0x166CCF45, 
0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2, 0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC, 0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9, 
0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693, 0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94, 0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D, 
};

        public static uint CRC32_Function(byte[] operand)
        {
            uint CRC32 = 0xffffffff;

            for (int i = 0; i < operand.Length; i++)
                CRC32 = (CRC32 >> 8) ^ CRC32Table[(CRC32 & 0xFF) ^ operand[i]];

            // Exclusive OR the result with the beginning value.
            CRC32 = CRC32 ^ 0xffffffff;

            return CRC32;
        }

        public static void CRC32(ref byte[] operand, IOutputNode SourceNode, IOutputNode TargetNode)
        {
            uint CRC32 = 0xffffffff;

            for (int i = 0; i < operand.Length; i++)
                CRC32 = (CRC32 >> 8) ^ CRC32Table[(CRC32 & 0xFF) ^ operand[i]];
            
            // Exclusive OR the result with the beginning value.
            CRC32 = CRC32 ^ 0xffffffff;

            operand = BitConverter.GetBytes(CRC32);

            if(!BitConverter.IsLittleEndian)
                Array.Reverse(operand);

            //CRC32Fn.CRC32Value = CRC32;
            //if (Coder.NeedsEncoding(TargetNode.TypeCode))
            String EncValue = Coder.MakeEncoded(operand, TargetNode.TypeCode);
            operand = TargetNode.OutputEncoding.GetBytes(EncValue);
        }

        //public static void CRC32Len(ref byte[] operand, IOutputNode SourceNode, IOutputNode TargetNode)
        //{
        //    // Make sure that if we are calling this function,  we have called CRC32 already
        //    Array.Reverse(operand);
        //    if (CRC32Fn.CRC32Value != BitConverter.ToUInt32(operand, 0))
        //        Log.Write("CRC32Fn.CRC32Len", "The function CRC32Len was called without a call to CRC32 first", Log.LogType.Error);

        //    Array.Reverse(operand);

        //    if(4 != operand.Length)
        //        Log.Write("CRC32Fn.CRC32Len", "The input CRC32 was not 4 bytes in length", Log.LogType.Error);
            
        //    // Get the number of least significant bytes to return
        //    String Value;
        //    if (!XMLProcInstCommands.GetCommandValue(TargetNode.PIText, "CRC32Len", out Value))
        //        Log.Write("CRC32.CRC32Len", "Could not get the value of the command 'CRC32Len' from processing instruction '" + TargetNode.PIText + "'", Log.LogType.Error);

        //    uint num;
        //    if(!UInt32.TryParse(Value, out num))
        //        Log.Write("CRC32.CRC32Len", "Could not convert the value '" + Value + "' of the command 'CRC32Len' to a UInt32", Log.LogType.Error);

        //    if((num > 4) || (num < 1))
        //        Log.Write("CRC32.CRC32Len", "The value '" + Value + "' of the command 'CRC32Len' needs to be between 1 and 4", Log.LogType.Error);

        //    // Zero out the unused bytes (so we can convert the correct value to a UInt32)
        //    for(int i = 0; i < 4 - num; i++)
        //    {
        //        operand[i] = 0;
        //    }

        //    Array.Reverse(operand);
        //    // Create the return array
        //    byte[] returnOperand = new byte[num];

        //    // Copy the desired number of bytes
        //    for (int i = 0; i < num; i++)
        //    {
        //        returnOperand[num - 1 - i] = operand[operand.Length - 1 - i];
        //    }
        //    operand = returnOperand;
        //}
    }
}
